Incorrect. The US was stating publicly that US policy was that Ukraine would join NATO. We had sold / sent over $3,000,000,000 in NATO weapons to Ukraine since 2014. US troops were training a battalion a month to NATO standards, on NATO weapons since 2014. We had (and have) active CIA and special forces in Ukraine directing defenses (one of the main reasons the Russians have been so very slow making advances in the Donbas).

Ukraine changed their post-Soviet constitution from stated neutrality to the goal of joining NATO.

Ukraine was doing just fine before the US started meddling in their elections, first in 2004, then backing the coup in 2014. There was ZERO Russian aggression against Ukraine from the end of the USSR to the coup in 2014.

Like Germany, Ukraine and Russia were steady business partners. Ukraine made billions per year on pipeline leases through the country. Russia had a leas on their military bases in the Crimea until 2042.

Russia did not want the Donbas or Crimea as part of Russia for multiple reasons. A huge one was (and is) financial. There are really good social programs and particularly pensions in the Donbas (big industrial area) that are very expensive.

Russia has not threatened to use nuclear weapons. Just the opposite. Russia has a "no-first strike" policy - unlike the US. If you actually read what the Russians say, rather than what the west says the Russians say, you'd know that.